Air compressors- oil lube vs oilless

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Easy Livin’ 3000

Minister of Fire
Dec 23, 2015
3,024
SEPA
Not having to buy oil sounds appealing, but I've found lubrication solves many of the issues I run across in life.

What's the case for one or the other?
 
Not having to buy oil sounds appealing, but I've found lubrication solves many of the issues I run across in life.

What's the case for one or the other?

I have to admit, I’m no expert in the latest on air compressors, but my impression from the research I did before buying my two compressors ten or fifteen years ago, is that there is some sacrifice in lifetime for going oilless.

My main shop compressor, 70 gallon / 7 hp vertical, is a traditional oil sump. It’s not a big deal, without combustion byproducts, you can go a decade between oil changes. It really doesn’t use any measureable amount of oil, I literally check it maybe once every 2 years, and might add some after 5 years. It is used a lot, at least for a weekend warrior, die grinding, needle scaling, RO sanding, and lots of painting.

My portable, which is really only used for nail guns, is oilless. All of my nailguns are teflon piston oilless designs, I prefer not blowing oil onto trim work I’m about to paint, so it works well. This compressor is also used to adjust the tire pressure on three cars four times per year, and the occasional bicycle tire, but that’s about it. How often does one really even run a portable compressor? The big traditional oil-sump compressor in the shop is always charged, and is my go-to, 99.9% of the time I need compressed air.
 
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I have to admit, I’m no expert in the latest on air compressors, but my impression from the research I did before buying my two compressors ten or fifteen years ago, is that there is some sacrifice in lifetime for going oilless.

My main shop compressor, 70 gallon / 7 hp vertical, is a traditional oil sump. It’s not a big deal, without combustion byproducts, you can go a decade between oil changes. It really doesn’t use any measureable amount of oil, I literally check it maybe once every 2 years, and might add some after 5 years. It is used a lot, at least for a weekend warrior, die grinding, needle scaling, RO sanding, and lots of painting.

My portable, which is really only used for nail guns, is oilless. All of my nailguns are teflon piston oilless designs, I prefer not blowing oil onto trim work I’m about to paint, so it works well. This compressor is also used to adjust the tire pressure on three cars four times per year, and the occasional bicycle tire, but that’s about it. How often does one really even run a portable compressor? The big traditional oil-sump compressor in the shop is always charged, and is my go-to, 99.9% of the time I need compressed air.
Everything you said makes sense and agrees with my experience and instincts. So, for my purposes, an oilless makes the most sense, with the understanding that it may be shorted lived. Will be using it infrequently, but when I need it, I really need it.

One last thing, any comments on decibels?
 
The quieter the better, always. But I’d put more emphasis on volume when discussing big, permanent shop compressors. When using the portable, I care less how loud it is, as I’m usually doing a specific job with it. The shop compressor is always live, and can kick on at any time as the room temperature changes, which can scare the hell out of you if it’s too loud. Plus, I don’t mind donning ear plugs for a specific job, but usually want to hear the radio when I’m diddling in the shop.
 
Here's the basic difference. "oil type" is a piston type compressor, tried & true old school. "oilless is a diaphragm type compressor. EVERYONE that I know that has one has had problems with them. Plus they are noisey. My old sears piston type is 35 years old and other than a pressure switch has never had a problem.

Spend the little extra and get a real compressor.
 
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Here's the basic difference. "oil type" is a piston type compressor, tried & true old school. "oilless is a diaphragm type compressor. EVERYONE that I know that has one has had problems with them. Plus they are noisey. My old sears piston type is 35 years old and other than a pressure switch has never had a problem.

Spend the little extra and get a real compressor.
I do like old school pistons.
 
For a portable you want oiless. For most people they last pretty long. I go through one every 3 or 4 years but it gets used allot and not really taken care of that well. My various shop compressors I have 3 in my different shops (work automotive and woodshop) are all oiled the oldest being a 30 year old Quincy in my woodshop.
 
For a portable you want oiless. For most people they last pretty long. I go through one every 3 or 4 years but it gets used allot and not really taken care of that well. My various shop compressors I have 3 in my different shops (work automotive and woodshop) are all oiled the oldest being a 30 year old Quincy in my woodshop.
If you were following best practices for maintenance, what would you be doing different? What is it about oilless that makes it better for portables? I'm not questioning that you are right, just have an intellectual curiosity.
 
If you were following best practices for maintenance, what would you be doing different? What is it about oilless that makes it better for portables? I'm not questioning that you are right, just have an intellectual curiosity.
Drain the water more often. Don't let them roll around in the back of a truck. But mainly don't make them run for hours constantly. I still do finish carpentry on the side and if I have someone helping me many times it doesn't shut off. Oiled compressors need to stay upright. If they are laid down you can't run them for a period of time.
 
From experience oiled compressors are the best bet.. After having 3 large oil-less compressors fall quite within a 1.1/2 years under light use last one did not last 4 hours. We went out and bought a old school compressor and never looked back. I have a small oil-less that i use for trim work and the odd roof repair less than a year old and already on its last legs taking forever to build pressure not alot of use less than 5 hours total. Once it calves i will be going back to old school for a portable and just put a dryer on it to remove any oil. If your looking for a shop rig go old school and it will never let you down.
 
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From experience oiled compressors are the best bet.. After having 3 large oil-less compressors fall quite within a 1.1/2 years under light use last one did not last 4 hours. We went out and bought a old school compressor and never looked back. I have a small oil-less that i use for trim work and the odd roof repair less than a year old and already on its last legs taking forever to build pressure not alot of use less than 5 hours total. Once it calves i will be going back to old school for a portable and just put a dryer on it to remove any oil. If your looking for a shop rig go old school and it will never let you down.
When you say, put a dryer on it, what do you mean?
 
There are in line filters/driers available often found in automotive paint suppliers.
 
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Let's be clear, there are dryers and there are separators. 99.999% of people are running a separator, and just incorrectly calling it a dryer. Also, 99.99% of them are using it wrong, making it almost entirely useless.

These devices, which all consist of some sort of reservoir designed to decrease air velocity, combined with some sort of screen to aid in separation, require some cooling between the source (compressor) and load (your tool) to do their job effectively. Most dryers consist of a separator preceded by some sort of cooling system, whether passive or active, and often followed by a desiccant system.

Yes, you need a separator on a permanent oil-sump compressor, but you also need some cooling mechanism between the compressor and separator for continuous use, to make it effective. This is what has made the oil-less numbers so popular for portable use, none of this crap is required on those.
 
I have a porter cable pancake style one that I bought from HD ten years ago, came with two small gauge trim nailers. It's just now starting to sound different and takes a bit longer to shut off. As a homeowner I use it often, for my purpose it's fine. If I had a garage I'd look for a bigger permanent oil lubed.
My only complaint is its loud! Not as loud as A ambulance coming up the street, that's what would likely happen if I attempted to blow up a kids pool float without a compressor!
 
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I keep an oil-lubed compressor in the shop and use it to fill a portable air tank for my mobile uses such as nail drivers, equipment tire inflating, etc. I find I can actually drive quite a few nails with a single tank charge and don't have to provide or listen to a compressor run.
I also recently invested in a small battery-powered inflator that has been really useful for equipment and vehicle tires.